1. Field of the Invention
This invention relates to a fast warmup, high capacity, no splash, no burnout, self-cleaning humidifier for a proof box used for proofing dough or the like prior to baking.
2. Description of the Prior Art
Humidifiers for proof boxes are generally well known. A proof box generally comprises an insulated cabinet in which the dough to be baked is placed and maintained at a desired temperature prior to baking, so that it may rise to the proper amount. As is well known to those skilled in the art, the relative humidity in the proof box should be maintained at about 80% in order to insure that the outer surface of the dough being proofed does not dry and crack as it is rising.
One approach taken by the prior art to supply humidity to the proof box is to inject steam into the proof box from an external source such as a steam line or a boiler. Such techniques are disclosed, respectively, in U.S. Pat. No. 4,023,406 issued May 17, 1977 to Burgess, Jr. and in U.S. Pat. No. 3,931,759 issued Jan. 13, 1976 to Hayashi.
Another approach is to use a steam generating apparatus located internally of the proof box. This technique disclosed by U.S. Pat. No. 3,518,949 issued July 7, 1970 to Stock and in U.S. Pat. No. 4,010,349 issued Mar. 1, 1977 to Lee. Disclosed in these patents is a proof box humidifier comprising a shallow pan, partially filled with water, having an immersion type heater located directly in the water. Such devices suffer from the drawbacks that minerals, scale and the like deposit on the immersion heaters, thereby reducing their efficiency in transferring heat to the water and thus reducing the amount of steam generated. A further drawback of such devices is that should the water supply fail and the immersion heaters run dry, they are likely to melt entailing the costly and time consuming replacement thereof.
A prior art device of this type is known to applicant and comprises a welded stainless steel pan about 18" long, 10" wide, and 4" deep in which 3 to 31/2" of water was maintained during use by a float controlled valve in a reservoir tank coupled to the pan by a straight conduit. Water was supplied to the valve by a 1/4" water line. Immersed in the water were three U-shaped, rod type electric heating elements of conventional construction rated at 2000 watts each. The heating elements were wired in a conventional delta configuration to a source of 3-phase AC 208 or 240 volt electric power. A thermostat was coupled to one of the heating elements to turn off power to the heating elements once a predetermined temperature was reached in order to protect the elements from burnout, should the pan run dry during use.